I have two manifold sets of the Ritchie Yellow Jacket gauges with 72" hoses and one set of direct couplers w/o hoses for ice machine work.
I've never had any gauges accurately calibrated like with a laboratory standard gauge. I often just check my suction gauge on the fly, like when a R22 compressor on a walk-in cycles off you watch where the gauge stops briefly at 58# (32 Deg) while any accumulated frost melts off the coil. That's accurate enough for me.
The high pressure gauge isn't as critical generally, but you can always check it by getting a pressure and temperature reading from a refrigerant tank that's been sitting in a stable temperature overnight, like at the shop.
Originally posted by frozensolid Transducers lie Thats why they have offsets.
gauges lie also, thats why they have adjustment screws.
Transducers are right more often than you think. I dont believe there always accurate, but they often are. lets face it, they take less abuse than most mechanics gauges. In the 8 years I have been doing supermarket work I have only found 2 faulty transducers and one that I had to put an offset into. Most of the transducers out there that fail or read wonky pressures are the ones that have been pulled into a vac, unless there designed for it never pull them into one.
My gauges have been knocked around and abused like most of us. The gauges have not have to be recalibrated once in 7 years! I use a richie manifold with a set of Marsh Gauges, I bought when Unitied use to sell them, they no longer handle them
I found a replacement set in a farmers supply house 20 miles north of me. I now have a set waiting for the original set to crap out
I swear by these suckers
Bob Key Largo
Replace mine twice a year. Used set for spare. Check valves one on set and not on others. 5' yellow jacket hoses and guages. They need to be on 0 when you start or add or subtract. Nice to have flutterless guages now so you don't have to kink the hose.